Method for producing fibers and non-woven fabrics by solution blow spinning and non-woven fabric produced thereby

ABSTRACT

The invention refers to the use of a parent solution (A) during a method for producing fibers for a fiber fleece by a so-called solution blow spinning. Water is used as solvent for the parent solution (A). At least one water-soluble polymer and preferably exactly one water-soluble polymer is dissolved in the water of the parent solution (A). The parent solution (A) additionally contains at least one surfactant and optionally plasticizer for the used at least one polymer respectively. By means of a parent solution (A) it is possible to produce fibers ( 24 ) by solution blow spinning.

The invention relates to the use of a parent solution for producingfibers, particularly microfibers or sub-microfibers or nanofibers bysolution blow spinning as well as such a spinning method for producingfibers and a non-woven fabric produced by the method. The solution blowspinning is a spinning method, in which a parent solution exits from atleast one output nozzle and is conveyed to a collector, in doing sosolid fibers are formed. Accordingly, the fibers are synthetic fibers.

Different methods exist for producing fibers. For example methods areknown during which fibers are produced by pressing of a liquid orsemi-liquid mass through openings. Such methods are referenced as meltor wet or dry spinning methods, depending on how the respective mass wasproduced or liquefied.

If particularly fine fibers shall be produced, i.e. fibers with a smallfiber diameter, centrifugal spinning methods as well as theelectrostatic spinning or the solution blow spinning are particularlysuitable. Such fibers are particularly necessary for manufacturing offilters. The drawback of the current methods is that usually solutionsare used for production of the fibers that are detrimental to theenvironment and/or incriminating for the health of the workingpersonnel. Also such solutions are often costly. Therefore, forenvironmental and cost reasons, water is increasingly provided assolution (i.e. the use of aqueous solutions of water-soluble polymers)in the afore-mentioned methods. Water is environmental friendly,non-toxic and cheap.

The use of water as solution for spinning methods is already known. Forexample JP 2010-150712 A shows a method for producing of fibers byelectrostatic spinning, in which aqueous solutions of water-solublepolymers are used.

The electrostatic spinning has a comparable low productivity forprinciple reasons. As a consequence, the fiber production byelectrostatic spinning is very expensive. The electrostatic spinning canbe economically used only for the production of fibers that are used invery upscale products.

U.S. Pat. No. 8,641,960 B1 describes a solution blow spinning, in whichsolutions of respective polymers are transferred by means of a processgas stream in solid fibers for producing of very fine polymer fibers.Such a solution blow spinning is of advantage compared withelectrostatic spinning, because it allows a productivity that is ahundred to a thousand times higher. However, so far producing fiberswith a sufficient or high quality from environmental friendly aqueoussolutions by solution blow spinning failed.

It can be considered as object of the present invention to producefibers and particularly high-grade fibers environmental friendly andefficiently.

This object is solved by the use of a parent solution in the solutionblow spinning with features of claim 1 as well as a method with thefeatures of claim 16.

According to the invention, the production of fibers by means ofsolution blow spinning uses a parent solution, in which water is used assolvent. At least the portion of water as solvent is in the range of 30%to 99%, preferably 50% to 95% and further preferably 60% to 90%. Atleast one and preferably exactly one water-soluble polymer is dissolvedin the solvent. Additionally the parent solution comprises at least onetenside. The tenside is a surface-active substance that can also bereferred to as surfactant.

It has turned out that due to the use of the described parent solution,the production of qualitative good and/or high-grade fibers having asubstantially constant fiber diameter can be achieved. The fibers can beproduced as microfibers, sub-microfibers or nanofibers, i.e. with afiber diameter in the micrometer range or sub-micrometer range ornanometer range by solution blow spinning. Thereby the sequence in whichthe added agents are dissolved in the solvent is not of particularimportance. The composition of the parent solution is significant.

During solution blow spinning one or more fluid jets are created withoutatomizing the liquid into spray. The liquid jets exit through a nozzleand are stretched by a process gas, particularly pressurized air. Indoing so, fibers are created. The liquid jets are preferablysubstantially orientated parallel with each other.

The created fibers are comprised preferably a ratio of length to a meanthickness of at least 100:1, preferably at least 500:1, preferably atleast 1000:1 and further preferably at least 10000:1. Preferably thefibers have a length of at least 1 mm, preferably of at least 3 mm andfurther preferably of at least 5 mm.

It is advantageous, if exclusively water is used as solvent in theparent solution. The at least one water-soluble polymer and the at leastone surfactant respectively are not considered as solvents.

It is advantageous, if the parent solution comprises exclusivelywater-soluble polymers. Other polymers that are not water-soluble arecontained in the parent solution. At least one of the containedwater-soluble polymers in the parent solution can be polyvinyl alcoholand/or polyvinyl methyl ether and/or polyethylene oxide and/or polyvinylpyrrolidone and/or polyethylene glycol and/or polyacrylic acid and/orpolyacrylamide.

It is advantageous, if the concentration of water in the parent solutionis in the range of 30 wt-% to 99 wt-%, preferably from 50 wt-% to 95wt-% further preferably from 60 wt-% to 90 wt-%.

The at least one water-soluble polymer can be selected from knownpolymers or polymer groups. The following list contains a non-exclusivelisting of usable water-soluble polymers:

-   -   cellulose derivatives, like methyl cellulose, sodium        carboxymethyl cellulose, hydroxymethyl cellulose, hydroxypropyl        cellulose, hydroxypropylmethyl cellulose;    -   natural rubbers like gelatin, metal alginates (Na, K, Ca, Zn,        Al), Agar;    -   starch derivatives like hydroxyethyl starch ether, hydroxypropyl        starch;    -   dextran, hydroxyalkyl dextran, carboxyl lower alkyl dextran;    -   water-soluble polysaccharides like xanthan, pullulan, ulvan;    -   polyamino acids with a free carboxyl group like aspartic acid or        glutamic acid;    -   polyalkylene glycol like polyethylene glycol and polypropylene        glycol;    -   synthetic derivatives of polyethylene oxide, polyvinyl alcohol,        polyvinyl methyl ether, polyvinyl pyrrolidone, polyallyl- and        diallylamines, polydimethylaminoethyl dimethacrylat, polyacylic        acid, polystyrene sulfonates, polyacrylamide, neutralized        carbopol rubber and copolymers and mixtures of the named        polymers.

In the parent solution can be contained exactly one or more of the namedpolymers.

Also copolymers or mixtures of the above-mentioned polymers can be used.

In the parent solution plasticizers can be contained for the present atleast one polymer, like for example polyethylene glycol, polypropyleneglycol, glycerine, trimethylolpropane, di-/tripropylene glycol orchemical compositions related therewith. When the concentration in theparent solution is determined, the plasticizers are added to the polymerportion and not to the solvent portion or the surfactant.

The concentration of the at least one water-soluble polymer in theparent solution is preferably in the range of 1 wt-% to 70 wt-%,preferably in the range of 5 wt-% to 50 wt-% and further preferably inthe range of 10 wt-% to 40 wt-% including an optionally presentplasticizer. The indicated concentration applies, if only onewater-soluble polymer is present in the parent solution as well as forparent solutions with a plurality of water-soluble polymers.

In a preferred embodiment the parent solution comprises exactly onewater-soluble polymer that can be completed with a suitable plasticizerfor the used polymer.

It is further preferred, if the concentration of the at least onesurfactant in the parent solution is in the range of 0.001 wt-% to 50wt-% and further preferably in the range of 0.01 wt-% to 5 wt-% andfurther preferably in the range of 0.1 wt-% to 1.5 wt-%. It ispreferred, if exactly one surfactant is contained in the parentsolution.

It is preferred, if a tenside is used that evaporates during thesolution blow spinning substantially or completely. Thus, no or onlyminor residuals of the surfactant remain in the produced fibers. Indoing so, it is avoided that residuals of the surfactant lead to anegative impact of the mechanical properties and/or the chemicalresistance of the produced fibers. Further, surfactant residuals can bedisadvantageous for medical applications.

For the parent solution A any surfactant can be used that is indicatedin the table below. In the table the trade name of the surfactant andindications of its composition are indicated respectively.

Name of surfactant Composition Abil Silicone-based surfactants AerosolMostly sulfosuccinates Aerosol OT (AOT) Sodium dioctylsulfosuccinateAkypo Mostly alkyl ether carboxylates Alkamide Alkanolamides AmietEthoxylated amines and amides Ammonyx Amine oxides Ampholak AmphotericsArlacel Fatty acid esters and ethoxylated fatty acid esters ArlatoneEthoxylated fatty acid esters Armeen Fatty amines Atlas Mostlyethoxylated compositions Atlox Surfactants and surfactant mixtures forpesticide formulations Berol Various, mostly ethoxylated compositionsBiodac Ethoxylated C10 alcohol Brij Ethoxylated fatty alcohols BritexEthoxylated fatty alcohols Calgene Various ester surfactants ChemalEthoxylated fatty alcohols Chemax Various ethoxylated compositionsChimipal Alkanolamides and various ethoxylated compositions Cithrol A,ML, MO Ethoxylated fatty acids und MS Cithrol, others Glycol andglycerol ethers Crodamine Amine oxides Crodet Ethoxylated fatty acidsDehydol Ethoxylated fatty alcohols Dehydrophen Ethoxylated alkylphenolsDehypon Ethoxylated fatty alcohols, special, e.g. end-blocked DobanolEthoxylated fatty alcohols Dowfax Diphenyloxide-based sulfonates ElfanVarious sulfates and sulfonates Emal Sulfates of alcohols andethoxylated alcohols Emcol Various contents Empicol Sulfates of alcoholsand ethoxylated alcohols, alkyl ether carboxylates Empilan Alkanolamidesand various ethoxylated compositions Empimin Sulfates andsulfosuccinates Emulan Various ethoxylated compositions EmulganteEthoxylated C16-C18 alcohols Emulson Various contents Ethylan Mostlyethoxylated compositions Eumulgin Various ethoxylated compositionsFindet Various ethoxylated compositions Fluorad Fluorocarbon-basedsurfactants Genapol Ethoxylated fatty alcohols Geropon Mostlysulfosuccinates and taurates Glucopon Sugar-based surfactants HamposylN-Acylsarcosinates Hostapur Alpha olefin sulfonates and petroleumsulfonates Iconol Various ethoxylated compositions Igepal Variousethoxylated compositions Imbentin Ethoxylated alkylphenols LialetEthoxylated fatty alcohols Lipolan Alpha olefin sulfonates LorodacEthoxylated fatty alcohols Lutensol Various ethoxylated compositionsMackam Amphoterics Macol Various ethoxylated compositions ManroSulfates, sulfonates and alkanolamides Marlipal Ethoxylated fattyalcohols Marlophen NP Ethoxylated nonylphenol Miranol ImidazolinesMirataine Betaines Monamid Alkanolamides Montane Sorbitan derivativesMyverol Monoglycerides Neodol Ethoxylated fatty alcohols Newcol Variouscontents Nikkol Various contents Ninol Alkanolamides Nissan NonionVarious ethoxylated compositions Trydet Ethoxylated fatty acids andester Trylon Ethoxylated fatty alcohols and oils Tween Ethoxylatedsorbitan Ufarol Alkylbenzene sulfonates and sulfates of fatty alcoholsand ethoxylated fatty alcohols Ufaryl Alkylbenzene sulfonates UfasanAlkylbenzene sulfonates Ungerol Sulfates of ethoxylated fatty alcoholsVaramide Alkanolamides Variquat Quaternary ammonium surfactants VolpoEthoxylated fatty alcohols Witcamide Alkanolamides Witconate Alkylarylsulfonates Witconol Glycol and glycerol esters Ninol AlkanolamidesNissan Nonion Various ethoxylated compositions

In one embodiment the parent solution can contain solid particles, e.g.organic and/or inorganic solid particles like SiO₂ TiO₂, ZrO₂, CuO, ZnOor Ag, preferably with particle diameters that are smaller than the meanfiber diameter.

Preferably the parent solution no additional components to the solvent,to the at least one polymer, to the surfactant and to an optionallypresent plasticizer and to optionally present solid particles.

During solution blow spinning the parent solution emanates from at leastone first output nozzle of a device. Concurrently a process gas emanatesfrom at least one second output nozzle. At least one second outputnozzle is assigned to each first output nozzle. The emanating processgas exits with high velocity. In doing so, the parent solution exitingthe first output opening is taken or carried by the process gas.

Preferably the process gas is supplied under a pressure of 0.1 to 1000psi, preferably from 5 to 80 psi and further preferably 10 to 60 psi tothe at least one second output nozzle.

In one embodiment air or pressurized air can be used as process gas. Theair can be supplied under a pressure of 10 to 80 psi to the at least onesecond output nozzle.

The parent solution can be supplied to the at least one first outputnozzle by a pump device. A metering pump, e.g. a gear pump, an eccentricspiral pump, a reciprocating piston pump, a hose pump, a diaphragm pumpor another displacement pump can be used as pump device.

Exactly one second output nozzle can be assigned to each first outputnozzle. In such an embodiment the second output nozzle can surround thefirst output nozzle partly or completely, preferably ring-shaped. In adifferent embodiment at least two second output nozzles are assigned toeach first output nozzle. The second output nozzles can be arrangeduniformly distributed around the parameter of the first output nozzles.Also linear arrangements of the output nozzles can be used.

The output direction that is defined by the at least one first outputnozzle and the output direction that is defined by the assigned at leastone second output nozzle can be orientated parallel to each other.Alternatively, it is also possible that the output direction of the atleast one second output nozzle is inclined relative to the outputdirection of the assigned at least one first output nozzle.

Due to the exiting process gas, a liquid jet of the parent solution isformed at least in a distance of some millimeters, e.g. of 0 to 100 mmor 0.5 to 20 mm or 1 to 5 mm. This liquid jet is carried or transportedby the process gas. During the transport of the parent solution in thedirection toward a collector, a contained solvent and/or the containedsurfactant vaporizes preferably substantially completely, at least to85% or at least to 90% or at least to 95% or at least to 99%. In doingso, the polymer contained in the parent solution solidifies, that is nolonger dissolved in the solvent. Solvent fibers created thereby arecollected on the collector.

The nozzle collector distance of the at least one output nozzle to thecollector has preferably an amount of at least 20 cm and furtherpreferably of at least 25 cm. In one embodiment the nozzle collectordistance can have an amount of about 30 to 70 cm. Preferably, the nozzlecollector distance is smaller than 200 cm and further preferably smallerthan 100 cm.

It is preferred that the boiling point of the solvent and/or thesurfactant is thus small that the solvent and/or the surfactantevaporates after exiting from the at least one first nozzle.

The process gas may have a focusing and/or concentrating effect onto theexiting solution. The formation of a fluid jet of the exiting parentsolution can be influenced by selection of process parameters, e.g. thecomposition of the parent solution and/or the temperature of the parentsolution and/or the temperature of the process gas and/or theenvironment temperature and/or the temperature of the output nozzlearrangement and/or the velocity of the process gas and/or the chemicalcomposition of the used process gas and/or a suction power of a suctiondevice arranged at the collector.

The fiber diameter of the produced fibers has typically an amount of onetwentieth to one thousandth of the opening diameter of the at least onefirst output opening. The fiber diameter is smaller than the diameter ofthe fluid jet exiting the at least one first output opening. A reductionof the fiber diameter relative to the diameter of the exiting fluid jetcan be achieved and set by process parameters, e.g. the velocity of theexiting process gas. If, for example, the exiting velocity of theprocess gas is increased, the liquid jet is so to speak stretched alongits path such that its diameter is reduced. Additionally, the solventand/or surfactant is evaporated such that the liquid volume is reducedafter exiting from the at least one first output nozzle.

Using the solution blow spinning it is for example possible to producefibers in the micrometer or sub-micrometer or nanometer range withdiameters of the at least one first output nozzle of, e.g. 0.2 to 1 mm.In one embodiment the produced fibers have a mean diameter of about 50nanometers to 3 micrometers.

The process gas can be supplied to the at least one second output nozzle(21) with a temperature of 0° C. to 100° C., preferably 10° C. to 90° C.and further preferably 20° C. to 80° C.

After the production of the fibers it can be advantageous, if apost-treatment of the fibers is performed, e.g. by irradiation with anenergy ridge radiation like UV light and/or a heat treatment and/or aplasma/corona treatment and/or a chemical treatment and/or anothertreatment for cross-linking. Due to such a post-treatment, it ispossible to obtain fibers that are not water-soluble. Such apost-treatment can be performed simply and cheaply.

All of the ranges indicated in the description (“from . . . to . . . ”)have to be apprehended as including the indicated range limit as long asnot indicated otherwise.

Preferred embodiments of the invention result from the dependent claims,the description and the drawings. In the following preferred embodimentsof the invention are explained in detail with reference to the attacheddrawings. The drawings show:

FIG. 1 a schematic diagram-like illustration of a device for producingfibers by solution blow spinning,

FIGS. 2 and 3 a schematic principle illustration of different outputnozzle arrangements respectively, each having a first output nozzle andat least one assigned second output nozzle in a top view on the outputnozzles,

FIGS. 4 and 5 a schematic principle illustration of different linearoutput nozzle arrangements of a plurality of first and second outputnozzles in a top view onto the output nozzles,

FIGS. 6 and 7 a schematic cross-section view of an embodiment of anoutput nozzle arrangement, each having at least one first output nozzleand at least one assigned second output nozzle respectively and

FIG. 8 a highly schematic illustration of an embodiment of a producedfiber.

FIG. 1 shows a device 10 for the execution of a solution blow spinningmethod. The device 10 has a reservoir 11 for providing a parent solutionA. A parent solution A is conveyed by a pump device 12 to a solutionfluid connection 13 of a spin nozzle device 14.

Additionally, the spin nozzle device 14 comprises a process gasconnection 15 by means of which a pressurized process gas G is suppliedto the spin nozzle device 14. The process gas G can be formed by air orpressurized air for example. It can be extracted from a pressurereservoir 16. Alternatively, instead of the pressure reservoir 16 acompressor or the like can be present in order to draw air from theenvironment and to provide pressurized air as process gas G. The processgas G can also be a different gas, like nitrogen, helium or hydrogen.

The spin nozzle device 14 has at least one first output nozzle 20. Atleast one second output nozzle 21 is assigned to each first outputnozzle 20. If a plurality of first output nozzles 20 is present, theycan have exit or emission directions that are orientated differently, asschematically illustrated in FIG. 1.

The at least one first output nozzle 20 is fluidically connected withthe solution fluid connection 13. The at least one second output nozzle21 is fluidically connected with the process gas connection 15. Thus,the parent solution A exits through the at least one first output nozzle20 and the process gas G exits through the at least one second outputnozzle 21.

The process gas G exiting concurrently with the parent solution Acarries the parent solution A and conveys it from the spin nozzle device14 away in direction toward a collector 22. Due to the high velocity ofthe process gas G, one or more liquid jets 23 of the parent solution Aare formed above the mouth of the respective first output nozzle 20.During the further path toward the collector 22, a solvent contained inthe parent solution A and where applicable additional liquid componentsof the parent solution A evaporate, such that solid fibers 24 are formedthat are collected at the collector 22.

The collector 22 can have moveable parts, e.g. a moving conveyor that ismoved via drive rolls 25. In a modification compared with theillustrated embodiment, the collector 22 can also be formed immovably,statically.

The collector 22 is preferably gas permeable and can be formed, forexample, by a grid or mesh-shaped carrier like a fine-meshed net. At theside opposite the spin nozzle device 14 of the collector 22 a suctiondevice 26 can be present. The suction device 26 can be configured tomove the fibers 24 forming between the spin nozzle device 14 and thecollector 22 toward the collector 22 by drawing of an air stream.

The nozzle collector distance z between the at least one first outputnozzle 20 and the collector 22 and/or between the at least one secondoutput nozzle 21 and the collector 22 has an amount of 20 cm or 25 cm.In the illustrated embodiment the nozzle collector distance z can havean amount of about 30 to 70 cm. Preferably the nozzle collector distancez is smaller than 200 cm and further preferably smaller than 100 cm.

In FIGS. 2 to 7 different embodiments of an output nozzle arrangement 30of the spin nozzle device 14 are schematically illustrated as an examplerespectively. The spin nozzle device 14 can comprise one or more of theillustrated output nozzle arrangements 30. These can be arranged ororientated parallel or inclined with each other at the spin nozzledevice 14. Each output nozzle arrangement 30 comprises at least one and,for example, exactly one first output nozzle 20 for the parent solutionA and at least one assigned second output nozzle 21 for the process gasG.

In the embodiment illustrated in FIG. 2 the nozzle arrangement 30contains exactly one first output nozzle 20 and exactly one assignedsecond output nozzle 21. The first output nozzle 20 is arranged in thecenter of a completely ring-shaped second output nozzle 21 thatsurrounds the first output nozzle 20 coaxially completely in theembodiment.

In the embodiment shown in FIG. 3 the output nozzle group 30 comprisesexactly one first output nozzle 20 and a plurality of assigned secondoutput nozzles 21 arranged adjacent thereto, e.g. four second outputnozzles 21. The number of the second output nozzles 21 can vary, whereinat least two second output nozzles 21 are present. The second outputnozzles 21 are preferably uniformly distributed in the peripheraldirection around the first output nozzle 20. The second output nozzlescan also have a curved slit form and partly surround the first outputnozzle 20 in its peripheral direction.

In general a cross-section form of the output nozzles 20, 21 can beselected arbitrarily. According to the embodiment, circular or circularring-shaped cross-sections are illustrated respectively. Also otherpolygonal or slit-like straight or curved cross-section contours can beprovided, particularly for the at least one second output nozzle 21 ofeach output nozzle group 30.

FIGS. 4 and 5 show only by way of example that the output nozzles 20, 21can be arranged in one or more rows side-by-side in a lineararrangement.

FIGS. 6 and 7 illustrate that the dashed dotted illustrated centerlength axis of the output nozzles 20, 21 of one output nozzle group 30can be orientated parallel with each other (FIG. 6) or alternatively canbe orientated inclined with regard to each other (FIG. 7). In theembodiment that is schematically shown in FIG. 7, the exit direction forthe process gas G of the at least one second output nozzle 21 isinclined compared with the exit direction of the parent solution A,according to the example, such that the process gas G is orientatedobliquely to the center length axis or the exit direction of the firstoutput nozzle 20 at several circumferential locations.

The mouth of the at least one first output nozzle 20 is arranged withdistance and preferably downstream of the process gas stream from themouth of the at least one assigned second output nozzle 21. The distancecan have an amount of, e.g. 0.5 to 20 mm or 1 to 10 mm or 1 to 5 mm or 2to 3 mm.

The orientations of the exit directions according to FIGS. 6 and 7 canbe provided for the output nozzle group 30 of FIG. 2 as well as for theoutput nozzle group 30 of FIG. 3.

For formation of the parent solution A at least one and preferablyexactly one water-soluble polymer from which the fibers 24 shall beformed, is dissolved in a solvent and according to the example in water.The parent solution additionally contains at least one surfactant. Alsofor the at least one polymer of the parent solution A a plasticizer canbe contained in the parent solution A. The polymer can be dissolved insolid form, e.g. as powder, in form of small balls or pellets or thelike in the water of the parent solution A that serves as solvent.

The concentration of the at least one water-soluble polymer in theparent solution A can have an amount of 1 wt-% to 70 wt-%, preferably 5wt-% to 50 wt-%, further preferably 10 wt-% to 40 wt-%. If a plasticizeris used for the at least one polymer, the values of the concentrationrefer to the total sum of the at least one polymer including theplasticizer.

In preferred embodiments the concentration of the water and the parentsolution has an amount of 30 wt-% to 99 wt-%, preferably 50 wt-% to 95wt-% and further preferably 60 wt-% to 90 wt-%.

In the embodiment the concentration of the surfactant in the parentsolution A has an amount of 0.001 wt-% to 50 wt-%, preferably 0.01% to 5wt-% and further preferably 0.1 wt-% to 1.5 wt-%.

The process gas G can be supplied at the process gas connection 13 witha pressure of up to 1000 psi, preferably with a pressure of 5 to 80 psi.If air is used as process gas G, the pressure can be in the range of 10to 60 psi. The process gas G has a temperature in the range of 0° C. to100° C., preferably 10° C. to 90° C. and further preferably of 20° C. to80° C. when supplied to the spin nozzle device 14. According to theexample, the process gas temperature of the process gas G during supplyto the spin nozzle device 14 is higher than the environment temperature,e.g. a room temperature, and can be in the range of 35° C. to 70° C.

The fibers 24 formed by polymer chains are obtained in the method,because the solvent, here water, and/or the at least one surfactantevaporates completely or at least partly on the way between the spinnozzle device 14 and the collector 22. That is the solvent and/or thesurfactant evaporate by at least 85% or at least by 90% or at least by95% or at least by 99%.

During the method by use of the device 10, the fibers 24 are formed. Afiber fleece of fibers 24 is created on the collector 22, whereinpreferably the fiber diameter is in the micrometer range, in thesub-micrometer range or in the nanometer range. The fibers 24 consistsubstantially of the polymer present in the parent solution A optionallyadditionally of the plasticizer used for the at least one polymer.

The created fibers 24 have preferably a ratio of a length L to a meanthickness D of at least 100:1, preferably at least 500:1, furtherpreferably at least 1000:1 and yet further preferably at least 10000:1.Preferably the fibers 24 have a length L of at least 1 mm, preferably ofat least 3 mm and further preferably of at least 5 mm.

Subsequently, examples 1 to 4 are indicated that describe a possiblecomposition of a parent solution A and features of the device 10.

EXAMPLE 1

For producing the polymer solution 10 wt-% of polyvinyl alcohol powder(with a molecular weight of 130000 u) are dissolved in distilled water(88 wt-%) and 2 wt-% of the surfactant polyoxyethylen(23)lauryl ether(known under the trade name Brij-35) are added. From the polymersolution fine fibers 24 are produced by the solution blow spinningmethod. The method is executed by using pressurized air as process gas Gthat is supplied with a pressure of 10 psi to the at least one secondoutput nozzle 21. The at least one first output nozzle 20 has a diameterof 0.6 mm (at the exit opening). The distance between the at least onefirst output nozzle 20 and the collector 22 has an amount of 65 cm. Thefibers produced with this method have a fiber diameter with a diameterin the range of 50 to 400 nm. The mean value of the diameter of thecreated fibers 24 is at 200 nm.

EXAMPLE 2

The polymer solution is produced of 12 wt-% polyvinyl alcohol (molecularweight 130000 u) that is dissolved in distilled water that is present inthe parent solution A with 87 wt-%. The parent solution A comprises 1wt-% isopropanol. The method is executed under use of pressurized air asprocess gas G that is supplied to the at least one second output nozzle21 under a pressure of 20 psi. The at least one first output nozzle 20has a diameter of 0.6 mm (at the exit opening). The distance between theat least one first output nozzle 20 and the collector 22 has an amountof 65 cm. The fibers 24 produced with this method have a fiber diameterwith a range of 100 to 450 nm. The mean value of the diameter of thecreated fibers 24 is at 240 nm.

EXAMPLE 3

10 wt-% polyvinyl alcohol (molecular weight 130000 u) and 2 wt-%polyvinyl methyl ether are dissolved in 87 wt-% water. The parentsolution A also contains 1 wt-% isopropanol. The method is executedunder use of pressurized air as process gas G that is supplied with apressure of 20 psi to the at least one second output nozzle 21. The atleast one first output nozzle 20 has a diameter of 0.8 mm (at the exitopening). The distance between the at least one first output nozzle 20and the collector 22 has an amount of 65 cm. The fibers 24 produced withthis method have a fiber diameter in the range of 100 to 500 nm. Themean value of the diameter of the created fibers 24 is at 250 nm.

EXAMPLE 4

3 wt-% of polyethylene oxide (molecular weight 600.000 u) are dissolvedin 96 wt-% of distilled water. The parent solution A also contains 2wt-% isopropanol. The method is executed under use of pressurized air asprocess gas G that is supplied under a pressure of 40 psi to the atleast one second output nozzle 21. The at least one first output nozzlehas a diameter of 0.6 mm. The distance between the at least one firstoutput nozzle 20 and the collector 22 has an amount of 65 cm. The fibers24 produced with this method have a fiber diameter in the range of 100to 500 nm. The mean value of the diameter of the created fibers 24 is at250 nm.

The four examples above or in general the spinning method according tothe invention can be further optimized by the use of additional and/oralternative surfactants. For example, each surfactant and/or polymer canbe used that is contained in the tables indicated at the beginning ofthe description.

Further specific examples result particularly from the selection of thecomposition of the components of the parent solution A in the ranges, asindicated in the description.

The features of the device 10 indicated in the examples 1 to 4 can alsobe used for other compositions of the parent solution A respectively.

The invention refers to the use of a parent solution A during a methodfor producing fibers for a fiber fleece by a so-called solution blowspinning. Water is used as solvent for the parent solution A. At leastone water-soluble polymer and preferably exactly one water-solublepolymer is dissolved in the water of the parent solution A. The parentsolution A additionally contains at least one surfactant and optionallyplasticizer for the used at least one polymer respectively. By means ofa parent solution A it is possible to produce fibers 24 by solution blowspinning environmental friendly.

REFERENCE LIST

-   10 device-   11 reservoir-   12 pump device-   13 solution fluid connection-   14 spin nozzle device-   15 process gas connection-   16 pressure reservoir-   20 first output nozzle-   21 second output nozzle-   22 collector-   23 liquid jet-   24 fiber-   25 drive roll-   26 suction device-   30 output nozzle group-   A parent solution-   D thickness of the fiber-   G process gas-   L length of the fiber-   z nozzle collector distance

1. A method for producing fibers and fleece materials (24) by solutionblow spinning using a parent solution (A), the method comprising:formulating the parent solution (A) using water as a solvent, dissolvingat least one water-soluble polymer in the parent solution (A), adding atleast one surfactant to the parent solution (A); and producing at leastone of a fiber and a fleece material by solution blow spinning using theparent solution (A).
 2. The method according to claim 1, whereinformulating the parent solution (A) includes using water exclusively asthe solvent.
 3. The method according to claim 1, wherein the at leastone water-soluble polymer in the parent solution (A) containsexclusively polymers that are water-soluble.
 4. The method according toclaim 1, wherein the at least one water-soluble polymer is one or anycombination of polyvinyl alcohol, polyvinyl methyl ether, polyethyleneoxide, polyvinyl pyrrolidone, polyethylene glycol, polyacrylic acid, andpolyacrylamide.
 5. The method according to claim 1, wherein theconcentration of the water in the parent solution (A) has an amount of30 wt-% to 99 wt-%.
 6. The method according to claim 5, wherein theconcentration of the water in the parent solution (A) has an amount of50 wt-% to 95 wt-%.
 7. The method according to claim 6, wherein theconcentration of water in the parent solution (A) has an amount of 60wt-% to 90 wt-%.
 8. The method according to claim 1, wherein theconcentration of the at least one water-soluble polymer in the parentsolution (A) has an amount of 1 wt-% to 70 wt-%.
 9. The method accordingto claim 8, wherein the concentration of the at least one water-solublepolymer in the parent solution (A) has an amount of 5 wt-% to 50 wt-%.10. The method according to claim 8, wherein the concentration of the atleast one water-soluble polymer in the parent solution (A) has an amountof 10 wt-% to 40 wt-%.
 11. The method according to claim 1, wherein theconcentration of the at least one surfactant in the parent solution (A)has an amount of 0.001 wt-% to 50 wt-%.
 12. The method according toclaim 11, wherein the concentration of the at least one surfactant inthe parent solution (A) has an amount of 0.01 wt-% to 5 wt-%.
 13. Themethod according to claim 12, wherein the concentration of the at leastone surfactant in the parent solution (A) has an amount of 0.1 wt-% to1.5 wt-%.
 14. The method according to claim 1, wherein the at least onesurfactant has a characteristic to at least partly evaporate during thesolution blow spinning.
 15. The method according to claim 1, wherein theparent solution comprises solid particles.
 16. The method according toclaim 1, further comprising: emitting the parent solution (A) from atleast one first output nozzle (20), emitting a process gas (G) from atleast one second output nozzle (21) that is arranged adjacent to the atleast one first output nozzle (20) while concurrently with the emittingthe parent solution (A) from the at least one first output nozzle. 17.The method according to claim 16, further comprising producing one orany combination of microfibers, sub-microfibers, nanofibers, and fleecematerials formed thereof.
 18. The method according to claim 16, furthercomprising supplying the process gas (G) to the at least one secondoutput nozzle (21) at a pressure of 0.1 to 100 psi.
 19. The methodaccording to claim 18, further comprising supplying the process gas (G)to the at least one second output nozzle (21) a pressure of 5 to 80 psi.20. The method according to claim 19, further comprising supplying theprocess gas (G) to the at least one second output nozzle (21) a pressureof 10 to 60 psi.
 21. The method according to claim 16, furthercomprising supplying the process gas (G) to the at least one secondoutput nozzle (21), wherein the process gas (G) has a temperature of 0°C. to 100° C.
 22. The method according to claim 21, wherein the processgas (G) has a temperature of 10° C. to 90° C.
 23. The method accordingto claim 21, wherein the process gas (G) has a temperature of 20° C. to80° C.
 24. The method according to claim 16, wherein the solvent in theparent solution (A) evaporates at least partly after the parent solutionis emitted from the at least one first output nozzle (20). 25.(canceled)